com.ifedorenko.m2e.sourcelookup.javaagent.ClassfileTransformer.java Source code

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Here is the source code for com.ifedorenko.m2e.sourcelookup.javaagent.ClassfileTransformer.java

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/*******************************************************************************
 * Copyright (c) 2014 Igor Fedorenko
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *      Igor Fedorenko - initial API and implementation
 *******************************************************************************/
package com.ifedorenko.m2e.sourcelookup.javaagent;

import org.objectweb.asm.ClassReader;
import org.objectweb.asm.ClassVisitor;
import org.objectweb.asm.ClassWriter;
import org.objectweb.asm.Opcodes;

class ClassfileTransformer {

    public byte[] transform(byte[] classfileBuffer, final String location) {

        final ClassReader r = new ClassReader(classfileBuffer, 0, classfileBuffer.length);
        final ClassWriter w = new ClassWriter(0);

        r.accept(new ClassVisitor(Opcodes.ASM5, w) {
            public void visitSource(String source, String debug) {
                String javaSource = source;
                if (debug != null) {
                    System.err.println("m2e SMAP merge is not supported!");
                    System.err.println(debug);
                } else {
                    StringBuilder smap = new StringBuilder();
                    smap.append("SMAP\n");
                    smap.append(javaSource).append("\n");
                    smap.append("Java\n"); // default strata name
                    smap.append("*S m2e\n");
                    smap.append("*F\n");
                    smap.append("1 ").append(source).append("\n");
                    smap.append("2 ").append(location).append("\n");
                    // JSR-045, StratumSection
                    // "One FileSection and one LineSection (in either order) must follow the StratumSection"
                    smap.append("*L\n");
                    smap.append("*E\n");
                    debug = smap.toString();
                }

                super.visitSource(javaSource, debug);
            };

        }, 0);

        return w.toByteArray();
    }
}